Systems such as missiles, spacecraft, airplanes or moving objects often employ guidance systems for orientating the system relative to earth. Some known ballistic missiles, for example, employ a guidance system to direct the flight path or trajectory of the missile based on a predetermined or desired target location. The guidance systems are typically inertial navigation or guidance systems that employ a measuring unit to detect the direction, position and/or speed of the missile.
Guidance systems such as, for example, inertial navigation or guidance systems can continuously calculate the position, orientation, and/or velocity (e.g., a direction and/or speed of movement) of a moving object without use of external references. An inertial guidance system includes an inertial measurement unit or an inertial measuring unit (IMU) having, for example, a processor, one or more motion sensing devices such as, for example, gyroscopes, accelerometers, and/or other motion-sensing devices or the like. The inertial guidance system is initially provided with its position and velocity from another source (e.g., a GPS satellite receiver or site survey, etc.), and thereafter computes an updated position and velocity by integrating information received from the motion sensors. Thus, an inertial guidance system does not require external references to determine its position, orientation, or velocity once its position has been initialized. Further, because inertial guidance systems do not require an external reference after initialization, the inertial guidance systems are immune to jamming and/or deception.
Due to their accuracy and resistance to jamming, inertial guidance systems are often used in intercontinental ballistic missiles (ICBM). An inertial guidance system is often disposed in a guidance section or portion of the ballistic missile, which is typically located beneath a weapons section or payload carried by the ballistic missile. For example, the inertial measurement unit typically includes a module to support or house motion-sensing devices or apparatus such as, for example, accelerometers, gyroscopes, and/or other motion-sensing devices that is disposed in the guidance wafer of the ballistic missile.
However, some known inertial guidance systems or inertial measurement units have a relatively large dimensional envelope or size (e.g., a height or length of approximately 20 inches). Due to the large dimensional envelope of the guidance system, a portion of the guidance system may protrude axially into adjacent wafers (e.g., a third motor wafer, a wafer downstage, a motor wafer, etc.) above and/or below the guidance wafer of the missile. In other words, a dimensional thickness or height of known guidance systems may be greater than a dimensional thickness or height of a guidance wafer in which the guidance system is housed when coupled to a ballistic missile.
As a result of the large dimensional envelope of the guidance system, the guidance section or portion of most ballistic missiles is removed and replaced with a new guidance section. Removing the guidance section of the ballistic missile often involves removing the weapons (e.g., nuclear warheads) of the ballistic missile and then reattaching the weapons when the guidance section is repaired or replaced.
For example, servicing the guidance system of ballistic missile typically requires removal of the guidance system via an opening provided in a top portion of the missile by removing a nose cone and a weapons wafer (which may include nuclear warheads) of the missile. In other words, the weapons wafer of the ballistic missile is typically removed to provide an access opening having an axis that is substantially coaxially aligned with a longitudinal axis of the missile to field service and/or replace a known guidance system and/or inertial measurement unit employed with a ballistic missile. Thus, accessing, servicing and/or replacing a guidance system of a ballistic missile often requires partial disassembly of the ballistic missile. Such an approach is labor intensive, relatively complex, and/or increases security risks and opportunities for damaging other sensitive equipment of the ballistic missile during disassembly.
In some instances, known ballistic missiles having nuclear warheads are often housed or contained within a protective concrete silo formed in the ground. In such examples, to gain access to the guidance wafer, the ballistic missile may need to be hoisted from the concrete silo containing the ballistic missile to expose the guidance section. Thus, the weapons may be exposed above ground and/or outside of the protective concrete silo. As a result, replacement of the guidance section often requires deployment of extensive security force and protocol when the weapons are exposed.
For example, to replace a guidance system of a ballistic missile stored in a silo, a silo cover is removed and sections of the ballistic missile are removed or lifted out of the silo, including the weapons wafer. For example, sections of the ballistic missile are lifted from within the silo via machinery starting with the nose cone. After the nose cone is removed, the weapons wafer is removed to enable access to the guidance system in the guidance wafer below it. Safety protocol may require a helicopter to be on standby to respond to any security breaches such as, for example, security breaches involving the removed weapons wafer. Additionally, such a process requires removal of the weapons wafer containing nuclear warheads from the protective concrete silo.
Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, area, or plate) is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, means that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Stating that any part is in contact with another part means that there is no intermediate part between the two parts.